I concur. My dogs all bark for the same reasons mentioned.
I did successfully stop the barking at the vacuum cleaner, by putting my vacuum cleaner attacker, Tres, on a short leash and making him stay by my side while I vacuumed. He couldn't get around in front of the machine to "herd" it. It only took one time and the fun was gone. I did the same thing with the lawn mower - made him walk with me behind the lawn mower while on lead. (I am sure my neighbors thought I was insane when I did that!)
I did successfully stop the barking at the vacuum cleaner, by putting my vacuum cleaner attacker, Tres, on a short leash and making him stay by my side while I vacuumed. He couldn't get around in front of the machine to "herd" it. It only took one time and the fun was gone. I did the same thing with the lawn mower - made him walk with me behind the lawn mower while on lead. (I am sure my neighbors thought I was insane when I did that!)